While playing back audio in the timeline or reviewing audio in the produced video you notice the audio skip, glitch, or not play the correct section. Sometimes you play the audio and it sounds correct, then you play the exact same section again and it plays different audio.
This is a known issue with certain MP3 files. We see it most with variable bitrate MP3 files. The best workaround is to import that file into a free program called Audacity and export it out as a WAV file and then use that WAV file in Camtasia..